1. Field of the Invention
This invention relates to a semiconductor device and a manufacturing method thereof, particularly, to a semiconductor device and a manufacturing method thereof in a cutting process of a semiconductor wafer attached with a supporting member.
2. Description of the Related Art
Conventionally, BGA (Ball Grip Array) type semiconductor devices have been known as a kind of a chip size package having almost same outside dimensions as those of a semiconductor die. In such a BGA type semiconductor device, a plurality of ball-shaped conductive terminals made of metal such as solder is arrayed in a grid pattern on one surface of the package, and electrically connected with the semiconductor die mounted on another surface of the package.
When this BGA type semiconductor device is mounted on electronic equipment, the semiconductor die is electrically connected with an external circuit on a printed circuit board by compression bonding of the conductive terminals to wiring patterns on the printed circuit board.
Such a BGA type semiconductor device has advantages in providing a large number of conductive terminals and in reducing size over other type semiconductor devices such as an SOP (Small Outline Package) and a QFP (Quad Flat Package), which have lead pins protruding from their sides. The BGA type semiconductor device is used as an image sensor chip for a digital camera incorporated into a mobile telephone, for example.
FIGS. 13A and 13B are schematic views of a conventional BGA type semiconductor device. FIG. 13A is a perspective view of the BGA type semiconductor device on its front side. FIG. 13B is a perspective view of the BGA type semiconductor device on its back surface.
A semiconductor die 101 is sealed between a first glass substrate 104a and a second glass substrate 104b serving as supporting members through resin 105a and 105b in the BGA type semiconductor device 100. A plurality of ball-shaped terminals (referred to as conductive terminals 111, hereafter) is arrayed in a grid pattern on a surface of the second glass substrate 104b, that is, on a back surface of the BGA type semiconductor device 100. The conductive terminals 111 are connected to the semiconductor dies 101 through second wirings 109. The plurality of second wirings 109 is connected with aluminum wirings pulled out from inside of the semiconductor dies 101, making the conductive terminals 111 electrically connected with the semiconductor dies 101.
Further explanation on a cross-sectional structure of the BGA type semiconductor device 100 will be given hereafter referring to FIG. 14. FIG. 14 shows a cross-sectional view of the BGA type semiconductor device 100 separated into individual dies along dicing lines.
A first wiring 103 is provided on an insulation film 102 on a front surface of the semiconductor die 101. The semiconductor die 101 is attached to the first glass substrate 104a with the resin 105a. A back surface of the semiconductor die 101 is attached to the second glass substrate 104b with the resin 105b. One end of the first wiring 103 is connected to the second wiring 109. The second wiring 109 extends from the end of the first wiring 103 onto a surface of the second glass substrate 104b. The ball-shaped conductive terminal 111 is formed on the second wiring 109 extended onto the second glass substrate 104b. 
The technology mentioned above is disclosed, for example, in Japanese Patent Application Publication No. 2002-512436.
In the manufacturing method described above, when the semiconductor wafer attached with the first and second glass substrates 104a and 104b is separated into individual dies along the dicing line, a dicing blade for cutting is aligned on a center of the dicing line. However, conventionally, it has been difficult to align the dicing blade on the center accurately, causing a problem of lowering cutting accuracy in dicing.